6.3. Power supply system of petrol engines
Fuel is sucked in from the fuel tank by the electric fuel pump and moves via the fuel filter to the fuel distributive highway. The regulator of pressure provides maintenance of pressure in fuel system at the level of 3.0 atm.
Through the electrooperated injectors fuel pulsewise is injected into the inlet pipeline located just before inlet valves of the engine. The control unit of the engine makes consecutive management of injectors according to an ignition order, regulates injection time and by that amount of injectable fuel.
The air necessary for formation of fuel mix is sucked in by the engine via the air filter and arrives through a butterfly valve, the air distributor and the inlet pipeline to inlet valves. The amount of the soaked-up air is regulated by the butterfly valve given by a cable from the accelerator pedal. The volume of the soaked-up air is defined by the sensor of an air stream (MAF). For increase in engine capacity the turbocompressor given by a stream of final gases is established.
The control unit of the engine defines optimum time of ignition, the moment of injection and amount of injectable fuel in coordination with other systems of the car.
Information from other sensors and the operating tension arriving to executive bodies ensures optimum functioning of the engine in any situation. If some sensors fail, the control unit switches in the mode of the emergency program to exclude possible damage of the engine and to provide the further movement of the car.
The arrangement of components of control systems of petrol engines is specified on illustrations.
Arrangement of components of a control system of the 4-cylinder engine
* On an illustration are not designated
Arrangement of components of a control system of the V6 engine
* On an illustration are not designated
The scheme components of a power supply system and release of OG are given in illustrations.
Scheme of an inlet air path and path of release of OG of 4-cylinder engines
The scheme of supply of fuel of petrol engines on the example of the 4-cylinder engine
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1 — the Fuel tank |
5 — the Fuel distributive highway |
Short description of the principles of functioning of some of sensors and actuation mechanisms of a control system of the engine
The sensor of provision of a butterfly valve (TPS) is built in in the executive mechanism of a butterfly valve and issues information on the current coal of provision of a butterfly valve on ECM. The second potentiometer reports to ECM data on basic value and forms a spare signal at failure of a potentiometer of a butterfly valve.
The sensor of provision of a bent shaft (CKP) transfers to the control unit information on the speed of a bent shaft and finding of the piston of the first cylinder to VMT.
The sensor of temperature of cooling liquid (ECT) represents the resistor with negative temperature coefficient which resistance decreases with growth of temperature.
The sensor of measurement of mass of air (MAF) represents the termoanemometrichesky measuring instrument which is built in to the inlet air highway of the engine and ECM when determining parameters of a dosage of air-fuel mix is used.
The system of ventilation of a fuel tank / catching of fuel evaporations (EVAP) consists of a coal adsorber and Ý/m the valve of management of a purge of the last. In an adsorber the fuel vapors which are formed as a result of its heating accumulate. During the operation of the engine the fuel evaporations which accumulated in an adsorber are extended to the inlet highway and go to combustion chambers.
Lambda probes measure the content of oxygen in the fulfilled gases (FG) before and after catalytic converters and transmit the corresponding signals to the control unit of the engine.